The present invention relates to a computer input device. More particularly, the present invention relates to a two-handed computer input device with an orientation sensor disposed thereon.
Many different types of user input devices are currently used for providing user input information to a computer. Such user input devices can include, for example, a point and click device (which is commonly referred to as a computer mouse), a keyboard, a joystick, and a track ball. Such user input devices all typically sense the movement of a movable element relative to a fixed base or housing portion and provide the computer with an input signal indicative of that relative movement.
Recently, free-space type user input devices have been introduced. Such devices use gravity sensing accelerometers to sense inclination of the user input device, in free space, relative to a gravity factor. Where a plurality of such sensors are provided, the sensors sense inclination of the user input device about a plurality of inclination axes. Such information is provided to a computer to control a cursor, a player, or a vehicle inside of a computer application or simulation, for example.
Many such input devices have one or more input modes. An input mode can be thought of as an input scheme that has a particular form, which is mutually-exclusive (or independent) of any other form of input. For example, pressing a button may be one type of input mode, while pushing a joystick to one side or another, is another type of input mode, which is independent of the button pushing mode.
Some types of user input devices assign more than two degrees of freedom to a single input mode. For example, a joystick which can be pushed along an X-axis, or a Y-axis has two degrees of freedom, while a joystick which can be pushed along an X or Y axis and which also can be rotated about its longitudinal axis to provide an input to the computer, has three degrees of freedom. It has been found that this type of user input device (one which provides more than two degrees of freedom per input mode) can exhibit a high degree of cross-axis interference. Cross-axis interference can be characterized by a user unintentionally actuating one degree of freedom while trying to actuate a separate degree of freedom. In other words, it is very difficult to prevent translational movement (moving a joystick along the X or Y axis) while attempting to perform a rotational movement (while attempting to rotate the joystick). Such interface between these degrees of freedom is cross-axis interference. It is believed that the tendency toward cross-axis interference increases quadratically with each added degree of freedom to any given input mode.
This same type of problem can be found in free-space type user input devices. For example, one commercially available free-space type user input device is a globe or sphere which is provided with orientation sensors that sense movement of the sphere about a pitch axis, a roll axis, and a yaw axis. It is very difficult for a user to attempt to execute rotation about the yaw axis without unintentionally executing rotation about either the pitch axis, the roll axis, or both.
Other types of free-space user input devices also exhibit other problems. For example, the Jacobs et al. U.S. Pat. No. 5,059,958 discloses a tilt sensitive non-joystick control box. However, the input device is simply a box with two buttons and with a tilt sensor disposed therein. Since one of the input modes in the Jacobs et al. device is a tilt or orientation input, the configuration of the Jacobs et al. device can promote ergonomically deficient hand position resulting in fatigue or discomfort. For example, when attempting to manipulate the Jacobs et al. device, the user may be required to maintain hand and wrist positions outside of ergonomically neutral flexion/extension and ulnar deviation ranges. Similarly, Jacobs et al. provides a very limited number of input modes.